Fluid pulsation dampeners

ABSTRACT

A pulsation dampener includes: a housing having in internal cavity; an expandable bellows positioned within the internal cavity of the housing, the expandable bellows having a proximal end, a distal end, and an expandable portion between the proximal and distal ends; a bellows support member coupled to an interior side of the distal end of the expandable bellows and extending longitudinally away from the distal end of the expandable bellows toward the proximal end of the expandable bellows; and a cap fixed with respect to the housing and positioned to support the bellows support member when the expandable bellows is in a longitudinally compressed configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/014,824, titled FLUID PULSATION DAMPENERS, filed on Sep. 8, 2020,which is hereby incorporated by reference herein in its entirety.

BACKGROUND Field

This disclosure generally relates to systems, methods, and devices fordampening pulsations in fluid piping systems.

Description

Hydraulic systems, such as fluid piping systems, are used to transportfluid under pressure in various applications. A fluid pump used in suchsystems creates pulsations that can cause a number of issues, includingwearing out components of the pump and other portions of the system overtime. A fluid pulsation dampener can be used to smooth out the fluidflow by absorbing such pulsations and providing extra pressure whenneeded.

SUMMARY

The disclosure herein provides various embodiments of fluid pulsationdampeners, including embodiments that have features enabling them toeffectively dampen pulsations in fluid piping systems that are subjectto high fluid pressures. For example, some embodiments comprise anexpandable polytetrafluoroethylene (PTFE) bellows that defines apressurized gas chamber on an exterior thereof and a liquid chamber influid communication with the piping system on the interior thereof. Theinterior of the bellows can include a rigid bellows support member thathelps to support the bellows in a compressed position when there is ahigh pressure differential between the gas chamber and the liquidchamber. Such a high pressure differential may be experienced, forexample, when the gas chamber is charged to a relatively high pressure,but there is little pressure in the liquid chamber to counteract thepressure in the gas chamber.

In a fluid piping system intended to operate with high pressure fluid,the gas chamber may need to be pressurized to a relatively high pressurein order to effectively dampen pulsations. In view of such a highpressure in the gas chamber, however, when the liquid chamber issignificantly less pressurized than the gas chamber, the high pressuredifferential could cause the expandable bellows to collapse in on itselfand suffer permanent damage. The bellows support member desirably solvesthis problem by providing both radial and longitudinal support to theexpandable bellows in the compressed configuration, to resist furthercompression or collapsing of the bellows in on itself.

According to some embodiments, a pulsation dampener comprises: a housingextending longitudinally from a first end to a second end, the housinghaving a longitudinally extending internal cavity; a cap attached to thefirst end of the housing, the cap having a proximal end and a distalend; an expandable polytetrafluoroethylene (PTFE) bellows positionedwithin the internal cavity of the housing, the expandable bellowscomprising a proximal end attached to the distal end of the cap, adistal end that is movable within the internal cavity along thelongitudinal direction, and an expansion portion comprising a pluralityof pleats between the proximal and distal ends of the bellows; a bellowssupport member coupled to an interior side of the distal end of theexpandable bellows and extending longitudinally away from the distal endof the expandable bellows toward the proximal end of the expandablebellows, the bellows support member comprising a rigid material having atapered shape extending longitudinally adjacent the pleats of thebellows, wherein the bellows support member is sized such that, in acompressed configuration with the bellows support member in contact withthe cap, opposing surfaces of adjacent pleats of the expandable bellowsare forced into contact with one another, wherein a proximal end of thebellows support member comprises a tapered shape configured to engageand be laterally centered by a complementary tapered shape in the distalend of the cap when the expandable bellows is in the compressedconfiguration, and wherein the bellows support member is sized such thatit fills at least 50% of a volume radially inward of the expandableportion of the bellows in the compressed configuration; a variablevolume gas chamber defined by at least the internal cavity of thehousing and an exterior surface of the expandable bellows; a gas valvein fluid communication with the variable volume gas chamber forintroduction of gas into the variable volume gas chamber; and a variablevolume liquid chamber defined at least by the cap, the bellows supportmember, and an interior surface of the expandable bellows.

In some embodiments, the interior side of the distal end of theexpandable bellows comprises a cavity and a radially inward extendingprotrusion, and a distal end of the bellows support member comprises aprotruding member shaped to fit at least partially within the cavity ofthe distal end of the expandable bellows and to be retained by theradially inward extending protrusion in a snap-fit arrangement. In someembodiments, a radially inner surface of the plurality of pleats definesan inner diameter of the expandable bellows, and wherein, with theexpandable bellows in a relaxed configuration, a total diametralclearance between the inner diameter of the expandable bellows and thetapered shape of the bellows support member extending longitudinallyadjacent the pleats is no greater than 15% of the inner diameter of theexpandable bellows. In some embodiments, the bellows support member issized such that it fills at least 75% of the volume radially inward ofthe expandable portion of the bellows in the compressed configuration.In some embodiments, the pulsation dampener is capable of withstanding asituation in which the gas chamber has a pressure that is at least10,000 psi greater than the pressure in the liquid chamber withoutpermanent deformation to the expandable bellows.

According to some embodiments, a pulsation dampener comprises: a housingextending longitudinally from a first end to a second end, the housinghaving a longitudinally extending internal cavity; a cap attached to thefirst end of the housing, the cap having a proximal end and a distalend; an expandable polytetrafluoroethylene (PTFE) bellows positionedwithin the internal cavity of the housing, the expandable bellowscomprising a proximal end attached to the distal end of the cap, and adistal end that is movable within the internal cavity along thelongitudinal direction; a bellows support member coupled to an interiorside of the distal end of the expandable bellows and extendinglongitudinally away from the distal end of the expandable bellows towardthe proximal end of the expandable bellows; a variable volume gaschamber defined by at least the internal cavity of the housing and anexterior surface of the expandable bellows; a gas valve in fluidcommunication with the variable volume gas chamber for introduction ofgas into the variable volume gas chamber; and a variable volume liquidchamber defined at least by the cap, the bellows support member, and aninterior surface of the expandable bellows.

In some embodiments, the bellows support member comprises a rigidmaterial. In some embodiments, the interior side of the distal end ofthe expandable bellows comprises a cavity and a radially inwardextending protrusion, and a distal end of the bellows support membercomprises a protruding member shaped to fit at least partially withinthe cavity of the distal end of the expandable bellows and to beretained by the radially inward extending protrusion. In someembodiments, the expandable bellows comprises an expandable portionbetween the proximal and distal ends of the expandable bellows, whereinthe expandable portion comprises a plurality of pleats, and a radiallyinner surface of the plurality of pleats defines an inner diameter ofthe expandable bellows, wherein the bellows support member comprises anattachment portion at a distal end of the bellows support member, anaxial support portion at a proximal end of the bellows support member,and a radial support portion between the attachment portion and theaxial support portion, and wherein, with the expandable bellows in arelaxed configuration, a total diametral clearance between the innerdiameter of the expandable bellows and the radial support portion of thebellows support member is no greater than 15% of the inner diameter ofthe expandable bellows. In some embodiments, a proximal end of thebellows support member comprises a tapered shape configured to engage acomplementary tapered shape in the proximal end of the cap when theexpandable bellows is in a compressed configuration. In someembodiments, the bellows support member is sized such that, in acompressed configuration with the bellows support member in contact withthe cap, opposing surfaces of adjacent pleats of the expandable bellowsare forced into contact with one another. In some embodiments, thepulsation dampener is capable of withstanding a situation in which thegas chamber has a pressure that is at least 10,000 psi greater than thepressure in the liquid chamber without permanent deformation to theexpandable bellows.

According to some embodiments, a pulsation dampener comprises: a housinghaving in internal cavity; an expandable bellows positioned within theinternal cavity of the housing, the expandable bellows comprising aproximal end, a distal end, and an expandable portion between theproximal and distal ends, wherein the proximal end of the expandablebellows is fixed with respect to the housing, and the distal end of theexpandable bellows is movable within the internal cavity with respect tothe housing; a bellows support member coupled to an interior side of thedistal end of the expandable bellows and extending longitudinally awayfrom the distal end of the expandable bellows toward the proximal end ofthe expandable bellows; a cap fixed with respect to the housing andpositioned to support the bellows support member when the expandablebellows is in a longitudinally compressed configuration; a firstvariable volume chamber defined by at least the internal cavity of thehousing and an exterior surface of the expandable bellows; and a secondvariable volume chamber defined by at least the cap, the bellows supportmember, and an interior surface of the expandable bellows.

In some embodiments, the housing comprises a gas port in fluidcommunication with a gas valve for introduction of a gas into the firstvariable volume chamber, and the cap comprises a fluid port forintroduction of a liquid into the second variable volume chamber. Insome embodiments, the expandable portion of the expandable bellowscomprises a plurality of pleats, and a radially inner surface of theplurality of pleats defines an inner diameter of the expandable bellows,wherein the bellows support member comprises an attachment portion at adistal end of the bellows support member, an axial support portion at aproximal end of the bellows support member, and a radial support portionbetween the attachment portion and the axial support portion, andwherein, with the expandable bellows in a relaxed configuration, a totaldiametral clearance between the inner diameter of the expandable bellowsand the radial support portion of the bellows support member is nogreater than 15% of the inner diameter of the expandable bellows. Insome embodiments, the expandable bellows comprises a polymer, and thebellows support member comprises a material having a higher stiffnessthan the polymer of the expandable bellows. In some embodiments, theexpandable bellows comprises polytetrafluoroethylene (PTFE) and thebellows support member comprises metal.

According to some embodiments, a bellows assembly for a fluid pulsationdampener comprises: an expandable bellows having a proximal end, adistal end, and a longitudinally expandable portion extending betweenthe proximal and distal ends; and a bellows support member coupled to aninterior side of the distal end of the expandable bellows and extendinglongitudinally away from the distal end of the expandable bellows towardthe proximal end of the expandable bellows, wherein the proximal end ofthe expandable bellows comprises an opening into a variable volumechamber defined by at least the distal end of the expandable bellows,the longitudinally expandable portion of the expandable bellows, and thebellows support member.

In some embodiments, the longitudinally expandable portion of theexpandable bellows comprises a plurality of pleats. In some embodiments,a radially inner surface of the plurality of pleats defines an innerdiameter of the expandable bellows, wherein the bellows support membercomprises an attachment portion at a distal end of the bellows supportmember, an axial support portion at a proximal end of the bellowssupport member, and a radial support portion between the attachmentportion and the axial support portion, and wherein, with the expandablebellows in a relaxed configuration, a total diametral clearance betweenthe inner diameter of the expandable bellows and the radial supportportion of the bellows support member is no greater than 15% of theinner diameter of the expandable bellows. In some embodiments, at leastthe longitudinally expandable portion of the expandable bellowscomprises polytetrafluoroethylene (PTFE). In some embodiments, theproximal end, distal end, and longitudinally expandable portion of theexpandable bellows comprise PTFE. In some embodiments, the expandablebellows comprises a polymer, and the bellows support member comprises amaterial having a higher stiffness than the polymer of the expandablebellows. In some embodiments, the expandable bellows comprisespolytetrafluoroethylene (PTFE) and the bellows support member comprisesmetal. In some embodiments, the proximal end of the expandable bellowscomprises a flange extending proximally, the flange comprising a largerdiameter at a proximal end of the flange than at a distal end of theflange. In some embodiments, the flange comprises one or more annulargrooves configured to accommodate an O-ring seal.

For purposes of this summary, certain aspects, advantages, and novelfeatures of the inventions are described herein. It is to be understoodthat not necessarily all such advantages may be achieved in accordancewith any particular embodiment of the inventions. Thus, for example,those skilled in the art will recognize that the inventions may beembodied or carried out in a manner that achieves one advantage or groupof advantages as taught herein without necessarily achieving otheradvantages as may be taught or suggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features, aspects, and advantages of the presentdisclosure are described in detail below with reference to the drawingsof various embodiments, which are intended to illustrate and not tolimit the disclosure. The features of some embodiments of the presentdisclosure, which are believed to be novel, will be more fully disclosedin the following detailed description. The following detaileddescription may best be understood by reference to the accompanyingdrawings wherein the same numbers in different drawings represents thesame parts. All drawings are schematic and are not intended to show anydimension to scale. The drawings comprise the following figures inwhich:

FIG. 1A is a side view of an embodiment of a pulsation dampener.

FIG. 1B is a cross-sectional view of the pulsation dampener of FIG. 1A.

FIG. 2 is a schematic diagram of an embodiment of a fluid piping systemthat comprises the pulsation dampener of FIG. 1A.

FIG. 3 is an enlarged cross-sectional view of the pulsation dampener ofFIG. 1A.

FIG. 4 is a cross-sectional view of a bellows support member of thepulsation dampener of FIG. 1A.

FIG. 5 is an enlarged cross-section view of a portion of the pulsationdampener of FIG. 1A.

FIG. 6A is a side view of another embodiment of a pulsation dampener.

FIG. 6B is a cross-sectional view of the pulsation dampener of FIG. 6A.

DETAILED DESCRIPTION

Although several embodiments, examples, and illustrations are disclosedbelow, it will be understood by those of ordinary skill in the art thatthe inventions described herein extend beyond the specifically disclosedembodiments, examples, and illustrations and include other uses of theinventions and obvious modifications and equivalents thereof.Embodiments of the inventions are described with reference to theaccompanying figures, wherein like numerals refer to like elementsthroughout. These drawings are considered to be a part of the entiredescription of some embodiments of the inventions. The terminology usedin the description presented herein is not intended to be interpreted inany limited or restrictive manner simply because it is being used inconjunction with a detailed description of certain specific embodimentsof the inventions. In addition, embodiments of the inventions cancomprise several novel features and no single feature is solelyresponsible for its desirable attributes or is essential to practicingthe inventions herein described.

Fluid piping systems are used in various industries to transfer liquidsuch as water, gas, oil, chemicals, and/or the like. A pump is oftenused to transmit such fluid from an upstream portion of the pipingsystem to a downstream portion. Pumps invariably introduce pulsations,vibrations, and/or other unwanted effects into the system, however,which can wear out system components over time and cause failure ofsystem components, among other potential issues. One way to reduce oreliminate such pulsations, vibrations, and/or the like is to install apulsation dampener, preferably near the pump on the downstream side. Onetype of pulsation dampener includes a sealed pressurized gas chamber anda liquid chamber, with a deformable bladder or other deformable memberseparating the two chambers. The fluid piping system is in fluidcommunication with the liquid chamber and, as pressure spikes areintroduced into the liquid chamber by pulsations from the pump, thosepressure spikes can be reduced and/or eliminated by deforming thebladder or other deformable member toward the pressurized gas chamber.Further, as the pressure output from the pump dips between the spikes,the bladder or other deformable member can deform toward the liquidchamber, adding pressure to the downstream flow. Such a pulsationdampener can desirably smooth out the downstream flow by reducing oreliminating the peaks and valleys in pressure output from the pump.

Such a fluid pulsation dampener design can work relatively effectively.Certain challenges arise, however, when attempting to design such apulsation dampener in high-pressure situations. In general, the gaschamber of a fluid pulsation dampener should be tuned to the pressureexpected in the liquid chamber, and it can be desirable to set the gaschamber pressure to be approximately 80% of the expected fluid pressure.Accordingly, the higher the pressure that is expected in the liquidchamber, the higher the pressure that the gas chamber should be chargedto. In some cases, it can be desirable to charge the gas chamber tosomewhere within a range of about 2,000 to 15,000 psi. In certainapplications, such as some applications in the oil and gas industry, itmay be desirable to pressurize the gas chamber of a pulsation dampenertoward the higher end, such as up to 10,000 to 15,000 psi or greater.When a similar level of pressure is present in the liquid chamber, suchhigh pressure may not be a significant issue, because the two pressuresdesirably balance each other out. Issues can arise, however, when thepressure in the liquid chamber is significantly reduced, such as in asituation where the fluid pump is turned off for maintenance or otherreasons. In such a case, the gas chamber of the pulsation dampener maybe charged to 10,000 to 15,000 psi or higher, with no counterbalancingfluid pressure in the liquid chamber. Such a high pressure differentialmay cause the deformable member to deform beyond its yield point,causing permanent damage and/or plastic deformation to the deformablemember.

A deformable member or bladder that separates a gas chamber from aliquid chamber in a pulsation dampener may utilize various materials.For example, one embodiment of a pulsation dampener may utilize rubberfor the deformable member. Such a deformable member may have arelatively high yield point/elastic limit and, depending on thestructural design of the deformable member and other portions of thepulsation dampener, may be able to withstand the types of pressuredifferentials that could occur when the gas chamber is pressurized to10,000 to 15,000 psi or more and there is no counterbalancing pressurein the liquid chamber. For example, if the rubber deformable memberencloses the gas chamber, and there is a high pressure differential,then the rubber deformable member may simply expand/blow up like aballoon, without causing permanent damage. In some cases, however, itmay be desirable to use different materials for the deformable memberthat have a lower yield point than rubber and can be significantlydamaged by such a pressure differential. For example, one material thatmay be desirable to use as a deformable member in a pulsation dampeneris polytetrafluoroethylene (PTFE). PTFE can be desirable, for example,because it is a relatively flexible or elastically deformable materialthat is also relatively inert, nontoxic, and nonflammable. PTFE is alsorelatively resistant to damage by harsh chemicals that may be present inthe fluid piping system. In general, however, a material like PTFEcannot withstand as much deformation or strain as rubber withoutsuffering permanent damage or plastic deformation.

The embodiments disclosed herein present various solutions to theseproblems. For example, some embodiments comprise a PTFE expandablebellows that incorporates an internal support structure. Such anexpandable bellows may be configured to be positioned within a cavity ofa housing, with a proximal end of the bellows fixed with respect to thehousing and a distal end of the bellows movable along a longitudinaldirection with respect to the housing. The distal end of the bellows mayinclude a supporting component that is attached to an internal side ofthe distal end and moves in the longitudinal direction along with thedistal end of the bellows.

The expandable bellows may have an expanded position and a compressedposition. For example, the expanded position may correspond to thedistal end of the bellows extending longitudinally to the end of theinternal cavity of the housing, and the compressed position maycorrespond to the distal end of the bellows retracting toward theproximal end of the bellows until the internal support member contacts acap or other structure that stops it from moving. It should be notedthat, although the expanded position is described as corresponding tothe distal end of the bellows contacting a distal end of the internalcavity of the housing, in practice the bellows might never reach such aposition if the pressure in the gas chamber is sufficiently high ascompared to the pressure in the liquid chamber.

In some embodiments, the internal support structure is configured toprevent the expandable bellows from collapsing in on itself (or at leastfrom collapsing in on itself to a point where plastic deformation wouldoccur) when the expandable bellows is in the compressed or collapsedposition and a relatively high pressure in the gas chamber wouldotherwise tend to cause the bellows to be damaged. For example, theinternal support structure may take the form of a generally cylindricaland/or tapered structure that, due to its attachment to the internalside of the distal end of the bellows will stop the distal end of thebellows from compressing further in the longitudinal direction when theinternal support structure is mechanically stopped by the cap or othercomponent of the pulsation dampener. Further, the internal supportstructure may desirably have a radial outer wall that is positionedrelatively close to an innermost wall of the expandable bellows, thuslimiting radial inward collapse of the expandable bellows in thecollapsed position. In some embodiments, the internal support structureis referred to as a bellows support member.

Another potential problem with some pulsation dampener designs,particularly some appendage style pulsation dampeners, is that someliquid may tend to be trapped inside the liquid chamber even when theliquid chamber is in its smallest volume configuration (for example,corresponding to the compressed configuration of the expandable bellowsdisclosed herein). For example, some pulsation dampeners may be designedsuch that, when the liquid chamber is in its smallest volumeconfiguration, the liquid chamber (or at least some portion of it) issealed off from the fluid piping system. In some embodiments, thepulsation dampeners disclosed herein are configured to allow all or amajority of the fluid in the liquid chamber to remain in fluidcommunication with the fluid piping system even when the expandablebellows is in the fully compressed configuration. Stated another way, insome embodiments disclosed herein, the liquid chamber is not sealed offfrom the fluid piping system when the expandable bellows is in the fullycompressed position. For example, as further discussed below, thebellows support member may be configured such that it is guided andsupported by the cap of the housing (or another component fixed withrespect to the housing) in the compressed configuration, without a fluidtight seal being created between the bellows support member and the cap.This can be beneficial over alternative designs that may cause at leasta portion of the liquid chamber to be fluidically sealed off from thefluid piping system when the liquid chamber is in its smallest volumeconfiguration.

Some of the various beneficial features of embodiments discussed belowinclude: a bellows support member that supports a bellows in a collapsedposition in both longitudinal and radial directions, a bellows supportmember having a proximal end that is shaped to be received by acorresponding shape in a cap that helps to center or otherwise positionthe bellows support member with respect to the cap, and a bellowssupport member that is configured to avoid trapping liquid the liquidchamber in the collapsed position.

Pulsation Dampening in Fluid Piping Systems

Turning to the figures, FIGS. 1A and 1B illustrate one embodiment of afluid pulsation dampener 100. FIG. 1A illustrates a side view of thepulsation dampener 100, and FIG. 1B illustrates a cross-sectional view.The pulsation dampener 100 is generally cylindrical in shape, althoughother shapes may also be used. FIG. 2 illustrates a schematic diagram ofthe pulsation dampener 100 in use in an appendage type configuration ina fluid piping system 200. The fluid piping system 200 comprises a pump220 that is in fluid communication with upstream piping 222 anddownstream piping 224. The pulsation dampener 100 is connected in fluidcommunication with the downstream piping 224 in order to reduce and/oreliminate pulsations, vibrations, and/or the like in the fluid flowoutput from the pump 220. The pulsation dampener 100 may be used influid piping systems having various types of pumps 220, such ascentrifugal, metering, hose, or air operated double diaphragm pumps.

The pulsation dampener 100 of FIG. 1B includes a housing 102 thatdefines an internal cavity having an expandable bellows 106 and a cap104 position therein. The expandable bellows 106 is movable within thecavity of the housing 102 and defines a volume of a variable volume gaschamber 108 on an outside of the expandable bellows 106, and of avariable volume liquid chamber 110 on an interior side of the expandablebellows 106. Further, as discussed in greater detail below, theexpandable bellows 106 has a bellows support member 380 coupled to aninterior side of the distal end of the expandable bellows 106. In thisversion of a pulsation dampener 100, the gas chamber is positioned atthe top, and the liquid chamber 110 is positioned at the bottom,however, other embodiments may position the chambers differently.

In the fluid piping system 200 of FIG. 2 , the pulsation dampener 100 isconnected in an appendage configuration. This means that the pulsationdampener 100 is connected in parallel with the output of the pump 220,using a single liquid inlet/outlet port through which fluid can enterand exit the liquid chamber 110 of the pulsation dampener 100. Theconcepts disclosed herein are not limited to such arrangements, however,and could be used with a pulsation dampener having separate liquid inletand outlet ports that may be, for example, connected in series with theoutput of the pump 220 instead of in parallel.

Example High Pressure Fluid Pulsation Dampener

FIGS. 3 and 4 illustrate additional details of the pulsation dampener100 of FIGS. 1A and 1B. FIG. 3 shows an enlarged version of thecross-sectional view of FIG. 1B, and FIG. 4 shows an enlargedcross-sectional view of only the bellows support member 380 of thepulsation dampener 100.

With reference to FIG. 3 , the pulsation dampener 100 comprises ahousing 102 defining an internal cavity into which the expandablebellows 106 and cap 104 are inserted. The cap 104 is desirably fixedwith respect to the housing 102 at a proximal end of the housing 102.The cap 104 further comprises a fluid port or fluid passage 336 thatallows a fluid piping system attached to piping attachment portion 334to be in fluid communication with the liquid chamber 110. The pipingattachment portion 334 may, for example, comprise a threaded hole forcoupling to a pipe, a connector, and/or the like.

The expandable bellows 106 comprises a proximal end 350, a distal end352, and an expandable portion 354 positioned between the proximal anddistal ends 350, 352. The expandable bellows 106 is desirably generallycylindrical in shape (e.g., the shape that would be formed if thecross-sectional shape of the bellows 106 shown in FIG. 3 were rotatedabout the longitudinal axis of the bellows 106). Such a shape can bedesirable, for example, to help resist damage when experiencing arelatively high pressure differential between the gas and liquidchambers 108, 110. Other shapes may be used, however.

Desirably, the proximal end 350 of the bellows 106 is captured betweenthe distal end of the cap 104 and an internal surface of the housing102, thus fixing the proximal end 350 of the expandable bellows 106 withrespect to the housing 102 and cap 104. Other techniques for fixing theproximal end 350 may be used, however. In some embodiments, the proximalend 350 of the expandable bellows 106, the cap 104, and/or the housing102 comprises one or more grooves to accommodate gaskets, such asO-rings 340 and 342, to help create a fluid and gas tight seal betweenthe cap 104, bellows 106, and housing 102.

The expandable portion 354 of the expandable bellows 106 desirablycomprises a plurality of folds that enables the distal end 352 of thebellows 106 to move longitudinally within the internal cavity of thehousing 102 without plastic deformation to the bellows 106. The foldsmay also be referred to as pleats or corrugations. In some embodiments,the expandable bellows 106, or at least the expandable portion 354 ofthe expandable bellows 106, is formed from polytetrafluoroethylene(PTFE). PTFE can be a desirable material to use, for example, because itis inert, nontoxic, and resistant to degradation by contact with harshchemicals or liquids in the liquid chamber 110. Desirably, theexpandable portion 354 is shaped using a configuration of folds thatwill allow the distal end 352 to move longitudinally back and forthbetween a fully compressed configuration (e.g., with the bellows supportmember 380 in contact with the cap 104) and a fully expandedconfiguration (e.g., with the distal end 352 of the bellows 106 incontact with the distal wall 353 of the internal cavity of the housing102) without causing permanent deformation to the expandable portion354. Some embodiments may not necessarily design the bellows 106 to beextendable all the way to the distal wall 353, since a properly setupfluid piping system may never require the bellows 106 to extend all theway to the distal wall 353. It can be desirable to design the bellows106 to extend all the way to the distal wall 353 without damage,however, at least to protect the bellows 106 from damage if, forexample, the gas chamber 108 is not tuned properly to the application(e.g., if it is undercharged or not pressurized at all). In someembodiments, the bellows 106 (or at least the expandable portion 354) isproduced by machining from a solid block of PTFE. For example, thebellows 106 of FIG. 3 may be machined in essentially the form it isshown in in FIG. 3 , and that may correspond to the relaxedconfiguration of the bellows 106. Other embodiments may use othermanufacturing methods.

With continued reference to FIG. 3 , the pulsation dampener 100 furthercomprises a bellows support member 380 positioned inside the expandablebellows 106 and desirably coupled to the inside of the distal end 352 ofthe expandable bellows 106. The bellows support member 380 comprises anattachment portion 360 at its distal end, an axial support portion 364at its proximal end, and a radial support portion 362 between theattachment portion 360 and axial support portion 364. The attachmentportion 360 is coupled to the distal end 352 of the expandable bellows106 such that the bellows support member 380 will move longitudinallywithin the pulsation dampener along with the distal end 352 of thebellows 106 as the pressure within the liquid chamber 110 changesrelative to the pressure within the gas chamber 108.

In this embodiment, the bellows support member 380 is coupled to thedistal end 352 of the bellows 106 by inserting attachment portion 360into a cavity 356 within the internal side of the distal end 352 of thebellows 106. Desirably, the cavity 356 comprises one or more radialinwardly extending protrusions 358 that fit into a correspondingradially inward extending portion 497 of the bellows support member 380(see FIG. 4 ). Similarly, the bellows support member 380 comprises aradially outward extending protruding member 495 that desirably fitsinto a radially outward extending portion of the cavity 356 positionedabove the radially inward extending protrusion 358. Accordingly, theattachment portion 360 of the bellows support member 380 is desirablycaptured and retained by the cavity 356 of the bellows 106. In someembodiments, these features form a snap-fit between the bellows supportmember 380 and the bellows 106. In some embodiments, these features arereversed, meaning that the distal end of the bellows comprises aprotrusion that snap-fits into a cavity of the bellows support member380. It should be noted that the shapes of the distal end 352 of thebellows 106 and the attachment portion 360 of the bellows support member380 shown in FIG. 3 are desirably symmetrical about their longitudinalaxes.

Other ways of attaching or coupling the bellows support member 380 tothe distal end 352 of the bellows 106 may also be utilized. For example,other embodiments may use fasteners, insert molding, a threadedconnection, and/or the like. The configuration shown in FIGS. 3 and 4may be desirable, however, at least because the tapered profile of theradially outward protruding portion 495 can ease the assembly of thebellows support member 380 into the cavity 356, and the radially inwardextending protrusion 358 can help to maintain the connection once made.Further, the bellows 106 is desirably shaped such that a higher pressurein the gas chamber 108 than in the liquid chamber 110 will tend to causethe bellows 106 to more tightly grip or maintain its hold on the bellowssupport member 380. For example, the distal-facing surface of the distalend 352 of the bellows 106 comprises an angled, chamfered, or contouredportion 359 that, along with the radial outer surface 361 of the bellows106 can help to cause of the radially inward extending protrusion 358 tobe biased radially inwardly by a positive pressure differential betweenthe gas chamber 108 and liquid chamber 110. Further, the radiallyoutermost surface 361 of the bellows 106 (or at least the radiallyoutermost surface 361 of the distal end 352 of the bellows 106) can besized to have relatively little clearance from the interior wall of theinner cavity of the housing 102. This can, for example, help to avoidthe radial inward protrusion 358 expanding outwardly and releasing thebellows support member 380 in response to a significantly positivepressure differential in the liquid chamber 110 with respect to the gaschamber 108. For example, the radially outermost surface 361 of thedistal end 352 of the bellows 106 may have a total diametral clearancefrom the inner wall of the cavity in the housing 102 of no more than0.05, 0.10, 0.15, or 0.20 inches.

Although in this embodiment there is desirably a single radial inwardprotrusion 358 that is annular in shape, other embodiments may comprisemore than one radial inward protrusion 358 that are each annular inshape and/or may not be annular in shape. It can be desirable for theradial inward protrusion 358 to be annular in shape, however, at leastbecause the hoop stress in such a ring-shaped or annular shapedprotrusion can further help to keep the bellows support member 380attached to the distal end 352 even when there is a significant positivepressure differential in the liquid chamber 110 versus the gas chamber108. Also, it should be noted that, in general, there will typically bea higher pressure in the gas chamber 108 than the liquid chamber 110.There may be some situations, however, when there is a significantlyhigher pressure in the liquid chamber 110 than the gas chamber 108, suchas in the case of an extreme pressure spike in the fluid piping systemand/or if the gas chamber 108 is not properly tuned to the application.In such situations, it would be desirable to still maintain the bellowssupport member 380 in engagement with the distal end 352, becauseotherwise, permanent damage to the assembly could occur and/or theassembly may need to be disassembled and repaired.

With continued reference to FIGS. 3 and 4 , the bellows support member380 comprises a radial or lateral support portion 362 and an axial orlongitudinal support portion 364. The axial or longitudinal supportportion 364 is shaped and configured to nest into support portion 366 ofthe cap 104 when the bellows 106 is in the fully collapsedconfiguration. For example, when there is little or no pressure in theliquid chamber 110 as compared to the gas chamber 108, the bellows 106will desirably be in the fully collapsed configuration. In thatconfiguration, the bellows support member 380 is desirably resisted frommoving any further longitudinally in the proximal direction (toward thepiping attachment 334) by the axial or longitudinal support portion 364engaging the support portion 366 of the cap 104. In some embodiments,such as the embodiment shown in FIGS. 3 and 4 , the support portions 364and 366 each comprise a tapered shape. These complementary taperedshapes can help to ensure that the bellows support portion 380 isradially or laterally centered in the assembly when in the fullycompressed configuration. This can help, for example, to prevent damageto the bellows 106 that could otherwise occur if the bellows 106 werecaused to be dislocated off-center and pressed into the interior wall ofthe housing 102. This can also help, for example, to ensure that theexpandable portion 354 of the bellows 106 is in a centered arrangementthat can best help the expandable portion 354 to avoid damage orpermanent deformation in response to a high pressure differentialbetween the gas chamber 108 and liquid chamber 110.

In various embodiments, either or both of the tapered surface 365 andradially extending flat surface 367 of the axial support portion 364 canbe configured to engage the support portion 366 and/or a flat distalface 369 of the cap 104 when the bellows 106 is in the fully compressedposition. In some cases, however, it can be desirable for only thetapered surface 365 to engage the support portion 366 in order to ensurethat the bellows support member 380 is centered with respect to the cap104.

In some embodiments, the attachment portion 360 of the bellows supportmember 380 also helps to resist damage to the bellows 106 in thecompressed configuration. For example, the attachment portion 360comprises a flat distal end (although other shapes may be used) thatsupports the “roof” of the bellows 106 (e.g., the center area of thedistal end 352) when in the compressed configuration. If the bellowssupport member 380 were, for example, tubular shaped instead of having asolid distal end, it could be possible for the roof of the bellows 106to be deformed into the inside of the bellows support member 380 in thecompressed configuration, thus damaging the distal end 352 of thebellows. This is also one of the reasons why attaching the bellowssupport member 380 to the distal/movable end of the bellows may be moredesirable than having a stationary bellows support member positioned atthe proximal end of the bellows. If the bellows support member werestationary at the proximal end of the bellows, then the bellows supportmember may need to have one or more fluid passages therethrough, whichwould also be areas that the bellows could be deformed into whencompressed under a high pressure differential.

It should be noted that desirably the bellows support member 380 and cap104 are made from metal or another relatively rigid material, anddesirably there is no elastomer seal between the bellows support member380 and cap 104. Accordingly, even when the axial support portion 364engages the support portion 366 of the cap 104, a fluid tight sealbetween the bellows support member 380 and cap 104 may not be formed.This can be a desirable feature, because it can allow most if not all ofany liquid that is remaining within the interior portion of the bellows106 to still be evacuated from the bellows 106 when the bellows 106 isin the fully contracted or compressed position (or at least to remain influid communication with the piping system when the bellows 106 is inthe fully contracted or compressed position). This can be beneficial,for example, because it can help to prevent trapping fluid within thebellows for extended periods of time. Although such a feature can bebeneficial, embodiments disclosed herein are not required to have such afeature, and in some cases, a fluid tight seal may be formed between thebellows support member 380 and the cap 104 in the compressedconfiguration, with or without an elastomer seal. Further, as describedbelow, some embodiments are configured such that, when the bellows 106is in the fully contracted or compressed position, the pleats of thebellows are compressed together, thus leaving little or no room forfluid between adjacent pleats. In such an embodiment, most if not all ofthe liquid within the bellows will have already been squeezed out of thebellows when the bellows support member 380 contacts the cap 104.

Another feature of the embodiment of FIG. 3 that can help to limit theamount of liquid trapped inside of the liquid chamber 110 is that thebellows support member 380 desirably takes up a significant amount ofthe internal volume of the bellows 106 in the compressed configuration.For example, the bellows support member 380 may be designed to fill atleast 40%, 50%, 60%, 70%, 75%, 80%, 90%, or more of the internal volumeof the expansion portion 354 of the bellows 106 when the bellows 106 isin the fully compressed position. Stated another, way, if the bellows106 is in the fully compressed position, a volume can be defined by theair space captured by the internal side of the pleats of the expansionportion 354, longitudinally between the proximal and distal ends of theexpansion portion 354. The bellows support member 380 may be seized tofill at least 40%, 50%, 60%, 70%, 75%, 80%, 90%, or more of that volume.In use, the gas chamber 108 is the portion of the pulsation dampener 100that is generally providing the pulsation dampening, and thus the liquidchamber 110 does not necessarily have to have a large volume availablefor liquid.

Additional features of the pulsation dampener 100 shown in FIG. 3include a gas valve 330, threaded holes 370 and 372, and a bolt 374. Thegas valve 330 is connected to the housing 102 and is desirably in fluidcommunication with the gas chamber 108 through one or more ports orfluid passages 332. In this embodiment, the gas valve 330 is desirably aone-way valve, such as a Schrader type valve, but other valves may alsobe used. In a typical usage, the gas valve 330 is utilized to tune thepressure of the gas chamber 108 to a particular application, and then isnot utilized again unless the pressure in the gas chamber 108 needs tobe changed due to changes in the application. The gas chamber 108 may becharged through the gas valve 330 with nitrogen, air, or othercompressible gases.

The threaded holes 370, 372 may be used for bolts that are used toattach the pulsation dampener 100 to a fluid piping system. In someembodiments, one or more of the threaded holes 370, 372 (in this caseonly threaded hole 372) may include a safety feature 373. In thisembodiment, the safety feature 373 is a lateral hole that fluidlyconnects the bore of the threaded hole 372 to a portion of the internalcavity of the housing 102. This feature may, for example, ensure thatthere cannot be a fluid pressure within the threaded juncture betweenthe cap 104 and the housing 102. Although only two threaded holes 370,372 are shown in this cross-sectional view, additional threaded holesmay be present in the cap 104.

Bolt 374 may, for example, function as a tie wire bolt. For example, thebolt 374 may function as an anchor for a tie wire that passes betweenbolt 374 and gas valve 330 as an additional safety feature to ensure gasvalve 330 does not unthread from the housing 102, thus releasing thehigh pressure within gas chamber 108.

It should be noted that, in the embodiment of FIG. 3 , the cap 104 is aunitary body that threads into the proximal end of the housing 102. Thecap 104 comprises both a proximal portion to which the fluid pipingsystem attaches and a distal portion that attaches to the proximal endof the bellows 106 and provides a support portion 366 for interactionwith the bellows support member 380. Other embodiments may not utilize aunitary body cap 104, however, and may use more than one component toaccomplish the various functions of cap 104. For example, one or morefirst components, which may be collectively referred to as the cap, maybe positioned within the housing 102 and act to capture the proximal endof the bellows 106 and/or to support the bellows support member 380 inthe compressed position. One or more second components may then bepositioned proximal to the cap and provide the function of fluidicallycoupling to the piping system. When the term cap is used herein, theterm cap is not necessarily intended to require that the cap be theoutermost component of the pulsation dampener that connects to the fluidpiping system. Rather, the term cap is intended to mean at least the oneor more components that captures the proximal end of the expandablebellows and supports the bellows support member, regardless of whetherthe cap also provides the connection to the piping system. Further, thecap does not necessarily have to be positioned within the housing insome embodiments. For example, the cap may comprise a component thatthread onto an external thread of the housing and abuts a proximal endof a cavity defined by the housing. In some embodiments, the one or morecomponents that captures the proximal end of the expandable bellowsand/or supports the bellows support member is referred to as a supportplate.

Bellows Support Member

FIG. 4 illustrates additional details of the bellows support member 380.FIG. 4 is a cross-sectional view of the bellows support member 380, andthe shape of the bellows support member is desirably symmetrical aboutits longitudinal axis (e.g., the shape that would be formed by rotatingthe cross-section of FIG. 4 about the bellows support member'slongitudinal axis). In addition to the cross-sectional view of thebellows support member 380, FIG. 4 also includes two vertical dashedlines 390 which are intended to represent the inner diameter of theexpandable portion 354 of the bellows 106 (defined by the radialinnermost edges of the folds of the expandable portion 354, as indicatedin FIG. 3 ).

As shown in FIG. 4 , the radial or lateral support portion 362 of thebellows support member 380 comprises a tapered shape having a largerdiameter D3 at the top and a smaller diameter D2 at the bottom. Someembodiments may not use a tapered shape, and for example may use acylindrical shape. It can be desirable to utilize an at least partiallytapered shape, however, such as to reduce turbulence in the fluid flowin and out of the area between the folds of the expandable portion 354and the area between the inner diameter 390 of the expandable portion354 and the outer surface of the radial support portion 362. Utilizing atapered shape can also help to minimize or eliminate trapping of fluidwithin the fluid chamber 110 when in the fully compressed position.

Regardless of whether the outer surface of the radial support portion362 is tapered, cylindrical, or shaped otherwise, it can be desirable tomaintain a relatively small total diametral clearance between the outersurface of the radial support portion 362 and the inner surface of theexpandable portion 354 of the bellows (represented by diameter D1 acrosslines 390). Maintaining a relatively small total diametral clearancebetween these components can help to avoid having the expandable portion354 collapse radially inwardly on itself when there is a high pressuredifferential between gas chamber 108 and liquid chamber 110 (or at leastto avoid collapsing radially inwardly an amount sufficient to causepermanent deformation). For example, in some cases, the gas chamber 108may be charged to 10,000 to 15,000 psi or higher, and the liquid chamber110 may be at atmospheric pressure before connection to the pipingsystem and/or before activation of the pump in the piping system.Without the bellows support member 380, and specifically the radialsupport portion 362 of the bellows support member 380, the expandableportion 354 could be caused to collapse too far radially inwardly,causing permanent damage and/or deformation to the bellows 106. In someembodiments, dimensions D1, D2, and D3 are approximately 1.45 inches,1.275 inches, and 1.37 inches, respectively. Other dimensions may beused, however, including various dimensions corresponding to thediametral clearance ratios described below.

In some embodiments, a diametral clearance ratio is defined as themaximum total diametral clearance between the outer surface of theradial support portion 362 and the surface represented by lines 390(diameter D1) when the expandable portion 354 is in a relaxedconfiguration (such as the position the expandable portion 354 willnaturally remain in if there is no pressure differential between the gaschamber 108 and liquid chamber 110), divided by the same diameter D1. Insome embodiments, the relaxed configuration is approximately halfwaybetween the fully extended and fully compressed positions. For example,in the embodiment of FIG. 4 that comprises a tapered outer surface ofthe radial support portion 362, the maximum total diametral clearancewould be dimension D2 subtracted from D1. The diametral clearance ratiowould then be that difference divided by diameter D1. In someembodiments, the diametral clearance ratio is desirably approximately12%. In some embodiments, the diametral clearance ratio is desirably nogreater than 5%, 7.5%, 10%, 12.5%, 15%, 17.5%, or 20%. In someembodiments, the diametral clearance ratio is desirably within a rangeof 5% to 15%, 7.5% to 20%, 5% to 17.5%, or 10% to 20%. It can bedesirable to have at least some clearance between the radial supportportion 362 and the inner diameter of the bellows 390, such as to allowfluid to pass therebetween, but it can also be desirable to not have toomuch clearance, which could lead to damage of the expandable portion 354of the bellows when there is a high pressure differential between thegas chamber 108 and liquid chamber 110.

FIG. 4 also illustrates that the radial support portion 362 comprises aheight H. The height H defines the longitudinal distance between theattachment portion 360 and the axial support portion 364. This can insome embodiments be an important dimension to help avoid damage to thebellows 106 when there is a high pressure differential between the gaschamber 108 and the liquid chamber 110. In some embodiments, it can bedesirable for the height H of the radial support portion 362 to beconfigured such that, in the fully compressed position, where the axialsupport portion 364 is supported by support portion 366 of the cap 104,the radial innermost portions 390 of the plurality of folds, pleats, orcorrugations are allowed to contact one another, and/or the opposingfaces 391 of the individual folds, pleats, or corrugations are allowedto come into contact with each other and/or to be compressed together.This can be desirable, for example, because if the expandable portion354 were still significantly expanded in the compressed position, thenthis would allow for additional space between the folds that thematerial of the expandable portion 354 could be deformed into by thehigh pressure in the gas chamber 108 and thus be permanently deformed ordamaged. Stated another way, the more compressed the expandable portion354 can be in the compressed position, the more the expandable portion354 will tend to act like a solid thick-walled tube, and thus the moreresistant the expandable portion 354 will be to lateral/radial movementand damage by a high pressure differential. The height H of theembodiment of FIG. 4 may be, for example, approximately 0.961 inches. Asdiscussed further below, various heights H may be used to adapt thebellows support member 380 to different applications.

Although it can be desirable to compress the individual folds, pleats,or corrugations together in the compressed position, in some embodimentsit may be desirable for the height H to be configured such that, in thefully compressed position, the radial innermost portions of theplurality of folds, pleats, or corrugations of the expandable portion354 of the bellows (e.g., the portions that define inner diameter 390)are almost contacting one another but not quite contacting one another.This may, for example, help to avoid any liquid being trapped betweenthe folds in the contracted position, while still maintaining at leastsome of the deformation limiting benefits of compressing the bellowsinto a solid tube-like structure.

The benefits described above are also some of the reasons why theconfiguration of FIG. 3 can be more desirable than a configuration wherethe liquid chamber is outside of the bellows and the gas chamber isinside of the bellows (e.g., if the locations of the gas and liquidchambers 108, 110 were reversed), particularly in high pressuresituations. In such a configuration, if the gas inside of the bellowwere pressurized to a high pressure (such as 10,000 to 15,000 psi orgreater), and the liquid outside of the bellows were not pressurized(and the liquid chamber was not sealed off from the external pipingsystem), then the bellows would tend to be stretched to its longestextension, and the innermost portion 390 of the folds of the expandableportion 354 would be forced radially outward. Stated another way, theindividual folds, pleats, or corrugations would expand outward againstthe inner wall of the housing cavity, potentially even expanding theinnermost portion 390 of the folds radially to be in contact with theinner wall of the housing. Such a situation may not necessarily damage abellows having a high yield point, such as certain bellows made ofrubber. Such a situation likely will damage a bellows having a loweryield point, however, such as a bellows made of PTFE. Testing has beenconducted on such a design, and even as little of a pressuredifferential as 500 psi has been shown to cause permanent deformation toa PTFE bellows. On the other hand, testing has also been conducted onthe design of FIG. 3 , and even a pressure differential of 20,000 psi(i.e. 20,000 psi in gas chamber 108 with no counterbalancing pressure inliquid chamber 110) resulted in no apparent damage to the bellows 106.

In some embodiments, the height H can be described as a ratio orpercentage of the full mechanical stroke of the distal end 352 of thebellows 106. For example, the full mechanical stroke may be defined asthe longitudinal distance that the distal end 352 of the bellows 106travels between the fully compressed position (when the axial supportportion 364 of the bellows support member 380 is supported by thesupport portion 366 of the cap 104), and the fully extended position (ifthe distal end 352 were to extend far enough to come in contact with thedistal surface 353 of the gas chamber 108. It should be noted that thisdefinition of the full mechanical stroke is used for the purposes ofdefining the height H as a ratio or percentage of that stroke; but, innormal use, it may not necessarily be intended that the distal end 352ever come in contact with the distal surface of the gas chamber 108. Insome embodiments, it can be desirable for the height H to beapproximately 90% of the full mechanical stroke. In some embodiments, itcan be desirable for the height H to be approximately, no more than, orno less than 70%, 80%, 90%, 100%, 110%, 120%, or 130% of the fullmechanical stroke. In some embodiments, it can be desirable for theheight H to be within a range of 70 to 110% or 80 to 100% of the fullmechanical stroke. In some embodiments, keeping the ratio toapproximately 90% or within a range of approximately 80 to 100% can bedesirable to achieve relatively high pulsation dampening capabilitywithin a reasonably sized overall package, while still maintaining theability to resist a high pressure differential between the gas chamber108 and liquid chamber 110 without permanent damage or deformation tothe bellows 106. The height H can also be determined by the distancebetween the interior surface of the distal end of the bellows 106 andthe distal face of the cap 104 (e.g., the two surfaces that contact thesurfaces of the bellows support member 380 that define height H in thecompressed position) when the bellows 106 is fully compressed. Thebellows 106 being fully compressed may be defined as the point at whichadjacent pleats of the expandable portion 354 come into contact witheach other and/or are compressed together sufficiently to remove anyvoid between the adjacent pleats. This can be an important distinctionbecause, if the bellows comprises PTFE or other relatively flexiblematerials, it may be technically possible to further compress thebellows beyond such a point, although permanent damage to the bellowscould be caused by such further compression. In order to prevent suchdamage, while still maintaining most or all of the benefits of havingthe bellows be fully compressed or at least close to fully compressedwhen the bellows support member 380 contacts the cap 104, the height Hmay desirably be within a range of 100% to 105% of the distance betweenthe inner surface of the distal end of the bellows 106 and the distalface of the cap 104 when the bellows 106 is fully compressed. In someembodiments, the desirable range of H may be 100% to 110% or 95% to110%. In some embodiments, the height H is desirably equal to or greaterthan the distance between the inner surface of the distal end of thebellows 106 and the distal face of the cap 104 when the bellows 106 isfully compressed.

Although, as described above, the embodiment illustrated in FIG. 3preferably does not form a fluid tight seal between the bellows supportmember 380 and support portion 366 of the cap 104 in the compressedconfiguration, some embodiments may form a fluid tight seal betweenthose components in the compressed configuration. For example, themanufacturing of the components may maintain close enough tolerancesthat a fluid tight seal (or substantially fluid tight seal) is formedwithout the aid of additional seals. Alternatively, one or more seals,such as O-rings or gaskets, may be included to form a fluid tight sealwhen in the compressed position. One reason such a configuration may bedesirable, is that such a configuration could trap liquid between thefolds of the expandable portion 354 of the bellows in the compressedconfiguration, and due to liquids generally being noncompressible, thetrapped liquid could desirably further help to keep the bellows 106 fromcollapsing in on itself in the compressed position when there is a highpressure differential between gas chamber 108 and liquid chamber 110. Asnoted above, however, it can also be desirable to have a design thatdoes not trap liquid within the bellows, and accordingly someembodiments do not form a fluid tight seal between the bellows supportmember 380 and the cap 104 in the compressed position.

Bellows Sealing Configuration

FIG. 5 illustrates an enlarged cross-sectional view of a portion of thepulsation dampener 100 of FIG. 3 . Specifically, the enlargedcross-sectional view of FIG. 5 illustrates a portion of the sealingconfiguration that captures the proximal end 350 of the bellows betweenthe housing 102 and cap 104. The proximal end of the bellows 350comprises a proximally extending flange 595 that is desirably capturedbetween a distal end of the cap 104 and an inner wall of the housing102. Desirably, the flange 595, and the walls it is captured between,comprise a tapered shape that has a smaller diameter at the top ordistal end than the diameter at the bottom or proximal end. Such atapered shape can be beneficial, for example, because it can help toensure adequate compression of the O-rings 340, 342 and/or the flange595 when the cap 104 is screwed into the housing 102.

Alternatively, adequate compression of these components to seal theassembly could be achieved by having the flange 595 extend directlyradially outwardly (e.g., extending perpendicular to a longitudinal axisof the assembly). Such a configuration could have potential problems,however, because a large bending or transverse stress would be appliedto the base of the flange 595 when the bellows is at the fully expandedposition. Stressing that joint repeatedly could eventually lead tofailure. Another alternative configuration could have the flange 595extend directly downward (e.g., extending parallel to the longitudinalaxis of the assembly). While such a configuration may minimize bendingor transverse stress at the base of the flange 595, sealing between theflange 595, cap 104, and housing 102 may not be ideal (and/or thestructural connection between these components may not be ideal),because there would be little or no compression of the flange 595itself. The design illustrated in FIG. 5 addresses these problems, forexample, by having the flange 595 extend at an angle between paralleland perpendicular to the longitudinal axis, which can limit the bendingor transverse stress on the base of the flange 595, while also allowingsome compression of the flange 595 when the cap 104 is tightened intothe housing 102.

With continued reference to FIG. 5 , the flange 595 in this embodimentcomprises one groove 591 that O-ring 340 fits into. Further, the cap 104comprises a groove 597 that O-ring 342 fits into. In other embodiments,the grooves may be positioned differently, such as there being nogrooves in the flange 595 or one or both of the O-rings 340, 342 havingcorresponding grooves in the flange 595. FIG. 5 further illustrates thatthe flange 595 has a radial inward protrusion 593 extending therefrom.This protrusion can be configured to fit into a corresponding groove ofthe cap 104. This feature may, for example, be beneficial to retain thebellows to the cap 104 during assembly. In some embodiments, it can bedesirable to position the protrusion 593 radially adjacent to the groove591, such as to increase a wall thickness of the flange 595 in thatarea.

Additional High Pressure Fluid Pulsation Dampener Embodiment

Turning now to FIGS. 6A and 6B, these figures illustrate an additionalembodiment of a fluid pulsation dampener 600. FIG. 6A is a side view,and FIG. 6B is a cross-sectional view. The fluid pulsation dampener 600is similar in many respects to the fluid pulsation dampener 100described above, and the same reference numbers are used to indicatesimilar features. Further, the description above of pulsation dampener100 is incorporated by reference in this section, and this section onlyfocuses on the differences between pulsation dampener 600 and pulsationdampener 100.

The main difference between pulsation dampener 600 and pulsationdampener 100 is that pulsation dampener 600 of FIG. 6B is configured tohave a longer mechanical stroke than pulsation dampener 100.Specifically, the internal cavity of the housing 102 is longer, theexpandable portion 354 of the bellows 106 is longer, and the radialsupport portion 362 of the bellows support member 380 is longer. Havinga longer mechanical stroke can, for example, enable the pulsationdampener 600 to more effectively dampen larger pressure spikes and/orpressure spikes that are longer in duration than with pulsation dampener100. Desirably, the radial support portion 362 of the bellows supportmember 380 comprises a height H (see FIG. 4 ) that is a similar ratio tothe full mechanical stroke as the height H of the radial support portion362 of the bellows support member 380 of FIG. 4 , as described above.Accordingly, although the bellows support member 380 of FIG. 6B islonger than the bellows support member 380 of FIGS. 3 and 4 , thebellows support member 380 of FIG. 6B may still have a similar ratio ofheight to full mechanical stroke as the bellows support member 380 ofFIGS. 3 and 5 .

Various other modifications, adaptations, and alternative designs are ofcourse possible in light of the above teachings. Therefore, it should beunderstood at this time that within the scope of the appended claims theinvention may be practiced otherwise than as specifically describedherein. It is contemplated that various combinations or subcombinationsof the specific features and aspects of the embodiments disclosed abovemay be made and still fall within one or more of the inventions.Further, the disclosure herein of any particular feature, aspect,method, property, characteristic, quality, attribute, element, or thelike in connection with an embodiment can be used in all otherembodiments set forth herein. Accordingly, it should be understood thatvarious features and aspects of the disclosed embodiments can becombined with or substituted for one another in order to form varyingmodes of the disclosed inventions. Thus, it is intended that the scopeof the present inventions herein disclosed should not be limited by theparticular disclosed embodiments described above. Moreover, while theinvention is susceptible to various modifications, and alternativeforms, specific examples thereof have been shown in the drawings and areherein described in detail. It should be understood, however, that theinvention is not to be limited to the particular forms or methodsdisclosed, but to the contrary, the invention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the various embodiments described and the appended claims.Any methods disclosed herein need not be performed in the order recited.

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements and/or steps areincluded or are to be performed in any particular embodiment. Theheadings used herein are for the convenience of the reader only and arenot meant to limit the scope of the inventions or claims.

1.-19. (canceled)
 20. A pulsation dampener comprising: a housing; anexpandable bellows comprising a proximal end, a distal end, and anexpandable portion between the proximal end and the distal end, theexpandable portion having a compressed configuration and an expandedconfiguration, wherein the proximal end of the expandable bellows is ina fixed position with respect to the housing, and wherein the distal endof the expandable bellows is positioned to be moveable along alongitudinal direction within at least a portion of the housing; a firstvariable volume chamber configured to have a smaller volume with theexpandable portion in the expanded configuration than with theexpandable portion in the compressed configuration; a second variablevolume chamber configured to have a larger volume with the expandableportion in the expanded configuration than with the expandable portionin the compressed configuration; and a bellows support member coupled tothe distal end of the expandable bellows, such that the bellows supportmember can move along the longitudinal direction with the distal end ofthe expandable bellows, wherein the bellows support member comprises asupport portion that is positioned to engage a support portion of thehousing with the expandable portion of the expandable bellows in thecompressed configuration, wherein the support portion of the bellowssupport member is positioned to be separated from the support portion ofthe housing with the expandable portion of the expandable bellows in theexpanded configuration, and wherein the bellows support member is sizedsuch that the bellows support member fills at least 50% of a volumeradially inward of the expandable portion of the expandable bellows withthe expandable portion in the compressed configuration.
 21. Thepulsation dampener of claim 20, wherein the engagement of the supportportion of the bellows support member and the support portion of thehousing with the expandable portion of the expandable bellows in thecompressed configuration is configured to limit movement along thelongitudinal direction of the distal end of the expandable bellowstoward the proximal end of the expandable bellows.
 22. The pulsationdampener of claim 21, wherein the engagement of the support portion ofthe bellows support member and the support portion of the housing withthe expandable portion of the expandable bellows in the compressedconfiguration is further configured to at least partially restrictmovement along a lateral direction of the support portion of the bellowssupport member with respect to the support portion of the housing. 23.The pulsation dampener of claim 22, wherein at least one of the supportportion of the bellows support member or the support portion of thehousing comprises an at least partially tapered shape that engages theother of the support portion of the bellows support member or thesupport portion of the housing.
 24. The pulsation dampener of claim 22,wherein each of the support portion of the bellows support member andthe support portion of the housing comprises an at least partiallytapered shape, the at least partially tapered shapes positioned to beengaged with one another with the expandable portion of the expandablebellows in the compressed configuration.
 25. The pulsation dampener ofclaim 20, wherein the housing comprises a cap that at least partiallyretains the proximal end of the expandable bellows in the fixedposition, and wherein the cap comprises the support portion of thehousing.
 26. The pulsation dampener of claim 25, wherein the proximalend of the expandable bellows comprises a flange that is sealed betweenthe cap of the housing and another portion of the housing.
 27. Thepulsation dampener of claim 20, wherein at least the expandable portionof the expandable bellows comprises polytetrafluoroethylene (PTFE), andthe bellows support member comprises a material having a higher rigiditythan the PTFE.
 28. The pulsation dampener of claim 20, furthercomprising: a valve in fluid communication with the first variablevolume chamber to allow introduction of gas to pressurize the firstvariable volume chamber; and a fluid port in fluid communication withthe second variable volume chamber to allow for fluid communicationbetween the second variable volume chamber and a fluid piping systemexternal to the pulsation dampener.
 29. A pulsation dampener comprising:a housing; an expandable bellows comprising a proximal end, a distalend, and an expandable portion between the proximal end and the distalend, the expandable portion having a compressed configuration and anexpanded configuration, wherein the proximal end of the expandablebellows is in a fixed position with respect to the housing, and whereinthe distal end of the expandable bellows is positioned to be moveablealong a longitudinal direction within at least a portion of the housing;a first variable volume chamber configured to have a smaller volume withthe expandable portion in the expanded configuration than with theexpandable portion in the compressed configuration; a second variablevolume chamber configured to have a larger volume with the expandableportion in the expanded configuration than with the expandable portionin the compressed configuration; and a bellows support member coupled tothe distal end of the expandable bellows, such that the bellows supportmember can move along the longitudinal direction with the distal end ofthe expandable bellows, wherein the bellows support member comprises asupport portion, the housing comprises a support portion, and at leastone of the support portion of the bellows support member or the supportportion of the housing comprises an at least partially tapered shapepositioned to engage the other of the support portion of the bellowssupport member or the support portion of the housing with the expandableportion of the expandable bellows in the compressed configuration, inorder to at least partially restrict movement along a lateral directionof the support portion of the bellows support member with respect to thesupport portion of the housing, and wherein the support portion of thebellows support member is positioned to be separated from the supportportion of the housing with the expandable portion of the expandablebellows in the expanded configuration.
 30. The pulsation dampener ofclaim 29, wherein the engagement of the support portion of the bellowssupport member and the support portion of the housing with theexpandable portion of the expandable bellows in the compressedconfiguration is further configured to limit movement along thelongitudinal direction of the distal end of the expandable bellowstoward the proximal end of the expandable bellows.
 31. The pulsationdampener of claim 29, wherein each of the support portion of the bellowssupport member and the support portion of the housing comprises an atleast partially tapered shape, the at least partially tapered shapespositioned to be engaged with one another with the expandable portion ofthe expandable bellows in the compressed configuration.
 32. Thepulsation dampener of claim 29, wherein the at least partially taperedshape is positioned to center the support portion of the bellows supportmember with respect to the proximal end of the expandable bellows withthe expandable portion of the expandable bellows in the compressedconfiguration.
 33. The pulsation dampener of claim 29, wherein thebellows support member is sized such that the bellows support memberfills at least 50% of a volume radially inward of the expandable portionof the expandable bellows with the expandable portion in the compressedconfiguration.
 34. The pulsation dampener of claim 29, wherein at leastthe expandable portion of the expandable bellows comprisespolytetrafluoroethylene (PTFE), and the bellows support member comprisesa material having a higher rigidity than the PTFE.
 35. A pulsationdampener comprising: a housing; an expandable bellows comprising aproximal end, a distal end, and an expandable portion between theproximal end and the distal end, the expandable portion having acompressed configuration and an expanded configuration, wherein theproximal end of the expandable bellows is in a fixed position withrespect to the housing, and wherein the distal end of the expandablebellows is positioned to be moveable along a longitudinal directionwithin at least a portion of the housing; a first variable volumechamber configured to have a smaller volume with the expandable portionin the expanded configuration than with the expandable portion in thecompressed configuration; a second variable volume chamber configured tohave a larger volume with the expandable portion in the expandedconfiguration than with the expandable portion in the compressedconfiguration; and a bellows support member coupled to the distal end ofthe expandable bellows, such that the bellows support member can movealong the longitudinal direction with the distal end of the expandablebellows, wherein the bellows support member comprises a support portionthat is positioned to engage a support portion of the housing with theexpandable portion of the expandable bellows in the compressedconfiguration, and wherein the proximal end of the bellows comprises aflange that is sealed between a first portion of the housing that is influid communication with the first variable volume chamber and a secondportion of the housing that is in fluid communication with the secondvariable volume chamber.
 36. The pulsation dampener of claim 35, whereinthe second portion of the housing comprises the support portion of thehousing, and wherein the second portion of the housing further comprisesa fluid passage in fluid communication with the second variable volumechamber to allow for fluid communication between the second variablevolume chamber and a fluid piping system external to the pulsationdampener.
 37. The pulsation dampener of claim 35, wherein the flange ofthe proximal end of the bellows extends proximally and comprises alarger diameter at a proximal end of the flange than at a distal end ofthe flange.
 38. The pulsation dampener of claim 35, wherein the supportportion of the bellows support member is positioned to be separated fromthe support portion of the housing with the expandable portion of theexpandable bellows in the expanded configuration.
 39. The pulsationdampener of claim 35, wherein at least the expandable portion of theexpandable bellows and the flange of the proximal end of the expandablebellows comprise polytetrafluoroethylene (PTFE), and the bellows supportmember comprises a material having a higher rigidity than the PTFE.